473b980bf9
All apps should display below system UI components such as the notification tray and power menu, so an overlay window is more appropriate. As a result, all apps has a separate window activity context, but some properties are delegated to the taskbar activity context. Taskbar should also be stashed while all apps is open. Change-Id: I593457708779d84a0ab8b949a966d247d0a2e1b7 Test: Manual Bug: 216843189 Fix: 217383817